Polymeric fabrics are used to make a variety of products, including water-absorbent articles. Such products include towels, wipes, and absorbent personal care products including infant care items such as diapers, child care items such as training pants, feminine care items such as sanitary napkins, and adult care items such as incontinence products. Polyolefin nonwoven fabrics are particularly suited for making these type products.
Water-absorbent articles, especially personal care absorbent articles, desirably include a nonwoven polymeric fabric which provides rapid intake of fluid such as water or an aqueous solution, minimal spreading of fluid on the fabric surface before fluid penetration, and wettability which is durable enough to survive multiple fluid insults. However, polyolefin nonwoven fabrics and other types of polymeric fabrics are normally water-repellent. Thus, to effectively absorb water, the polymeric fabrics must be treated to become hydrophilic.
One method of making polymeric fabrics more wettable is applying a surfactant to the surface of the fabric. Conventional surfactants for treating polymeric fabrics include non-ionic surfactants such as octylphenoxypolyethoxy ethanol. Although such conventional surface treatments are effective to make polymeric fabrics wettable, there are still some problems. For example, conventional surface treatment compositions such as the foregoing are relatively easily rubbed-off the fabric and are also easily washed-off the fabric when the fabric is wetted. Such surface treatments are often substantially completely removed from the polymeric fabric after only one liquid insult or washing. After the surface treatment is removed, the polymeric fabric again becomes water-repellent and less effective to absorb water. Moreover, to compensate the inability of conventional surface treatments to survive use, conventional surface treatments are often applied to primary fabrics in large quantities and thus the cost of the treated fabric is increased.
U.S. Pat. No. 5,057,361 to Sayovitz et al. discloses a durable surface treatment for improving the wettability of polymeric fabrics. That patent discloses the treatment of polymeric fabric with a primary surfactant having a low solubility in water. The primary surfactant is applied to the fabric in an aqueous solution along with a fugitive co-surfactant or co-wetting aid which is functional to wet the polymeric fabric during application of the primary surfactant and provides for substantially uniform distribution of the primary surfactant onto the fabric.
Although the surface treatment disclosed in U.S. Pat. No. 5,057,361 is an effective and durable surface treatment for improving the wettability of polymeric fabrics, there is still a need an even more durable surface treatment for improving the wettability of polymeric fabrics.